This invention relates to a programmable automatic controller for operating one or more machines having a plurality of functional components which operate in a timed relationship with one another.
In the past there has been a great need for a programmable controller for operating complex machines having components which operate in timed relationship with one another. For example, in the glass forming technology, glass forming machines are typically comprised of a plurality of individual sections which are integrated into a single plural section machine fed by a single source of molten glass. The sections are operated in synchronism in such relative phase relationship as to permit the several sections to acquire gobs in ordered sequence from a single gob feeding means. Thus, as one of the sections is taking a gob from the feeding means, another section is delivering a finished article to an output conveyor and the other intermediate sections are engaged in various forming steps intermediate the taking of a gob in the production of the finished ware.
Further, it has been customary in the past to provide two molds in each section of an individual section machine whereby a gob is received in a first mold called the blank or parison mold for the initial process of forming a parison, followed by a transfer of the parison to a second mold called the blow mold for final blowing of the article. By this means each section of the machine is operating simultaneously upon two workpieces. In order to control the operation of the various functional components of the glass forming machine, a means must be provided for actuating each of the elements in a preselected cyclic time format so that the operation of one element does not interfere with, but rather complements, the operation of the other components.
The several functional elements of the glass forming stations in the individual section machine are typically driven by pneumatic pressure which is controlled by either a mechanical synchronizing means in the form of rotary drums or by an electronic timing circuit. An example of a prior art controller utilizing mechanical synchronizing means is disclosed in Ingle U.S. Pat. No. 1,911,119. The Ingle glass forming machine is cumbersome and more importantly is difficult to adjust so that the timing of the operation of the various components of the machine can be varied. An example of a prior art controller utilizing electronic timing circuits is U.S. Pat. No. 3,762,907 issued to Richard M. Quinn et al and assigned to the common assignee herewith. Some prior art controllers do not include an easy, simplified means for adjusting the time of operation of the various elements in a machine cycle while the machine is operating and accordingly lacks the flexibility desired in an automatic controller. A further drawback of the prior art has been the fact that no means has been provided for initiating a starting or stopping sequence of the machinery when the machine is to be started or stopped, respectively. For example, in stopping a section of a glass forming machine it is highly desirable to clear the last bottle, to have the transfer arm in the inverted position and the neck rings open. To properly accomplish this in an ordered sequence, the stop cycle should begin with the molds open. In the past, no such provision was made for initiating the stop cycle of a machine at a predesignated interval in the machine cycle and for effecting a predetermined operation of the components of the machine such that the shutting down of the machine occurs in a safe and orderly fashion.
A further drawback of the prior art is the fact that control systems have typically been designed to control the operation of a specific machine, such as for example, a glass forming machine, a molding machine, welding machines, etc. There is accordingly a need for a flexible automatic controller which can be easily programmed to control a plurality of different types of machines which operate on a cyclic or timed relationship.
It therefore is an object of this invention to provide a flexible, programmable automatic controller for operating machines of various types.
It is another object of this invention to provide an automatic controller having a simplified and efficient means for adjusting the timing of the operational functions of a machine with a high degree of accuracy while the machine is running.
It is yet another object of this invention to provide a programmable automatic controller for controlling a plurality of machines which operate in a predetermined, interdependent timed relationship with respect to one another.